The invention concerns an evaporation-cooled internal combustion engine wherein a liquid coolant can flow through a pressurizable cooling system that includes a surge tank and a radiator.
Such an internal combustion engine is known from the U.S. Pat. No. 4 648 356. The cooling system essentially comprises a water jacket on the internal combustion engine, a radiator in the form of a condensation radiator, a condensate tank, and a tank divided into two compartments by a partition. The compartment facing away from the cooling system is open to the atmosphere. The objective is to temporarily extract the air from the hermetically sealed system and keep it away from the condenser in order to improve the system's function. Air, which is detrimental to the system, is stored in the partitioned tank while the engine is operating and warm, and is returned to the system as the engine cools in order to prevent the occurrence of a vacuum.
It must be taken into consideration that much of the cooling system becomes wet when the engine cools. When the ambient temperature is low, the moisture can freeze inside the system and lead to malfunction or destruction of the cooling system. The design also requires delicate sensors to detect the level of the liquid. It is difficult to control the cooling action precisely. The volume of condensate cannot be regulated in relation to its temperature, a situation that can occasion stress cracks in the engine parts when the temperature of the condensate differs extensively from that of the components. It is also comparatively complicated to replenish the system with coolant, which must be precisely measured.